1. Field of the Invention
This invention is an improvement over the invention disclosed and claimed in U.S. Pat. No. 4,550,728 to Runyon and However, and also relates to a high frequency probe type epilator.
This invention is concerned with an epilation procedure, and a control apparatus and a probeholder used in connection with the epilation procedure.
More particularly, the invention is concerned with precise control of intensity (power level) and timing and dynamic power control based on impedance variation. Variations in the depth of insertion and hair characteristics impact the initial impedance, and the application of power to the follicle results in dynamic impedance changes. The impedance is measured during the pulse and the power is compensated to minimize skin reaction and sensation to the patient.
The invention is also concerned with a novel probeholder.
2. Description of the Prior Act
The prior U.S. Pat. No. 4,550,728, while it also relates to an RF epilator procedure and is also concerned with safety controls, relied on open loop electrical circuit characteristics to select power setting. This resulted in non-linear power variations, as well as, uncontrolled response to variations in impedance during the pulse. The process of RF epilation is performed by inserting an insulated bulbous tipped probe into a follicle and applying a controlled burst of RF energy to the probe. The probe tip concentrates the energy at the germinative portion of the hair (dermal papilla) destroying the follicle's capacity to regenerate itself. Operators, based on their experience, select the timing and intensity of the RF power pulse to be applied. The actual pulse length will not exceed these settings. During the pulse the power delivered is based on the intensity setting selected by the operator as impacted by the inherent response of the circuit to variations of the impedance reflected to the power amplifier output. The impedance as seen at the probe tip varies throughout the duration as a function of skin characteristics, hair size and depth of penetration. During the pulse dynamic changes in the impedance occur as energy is applied to the tissue.
With the prior heretofore known probeholders, an operator using the probeholder became part of the RF load. Different operators presented a different load impedance to the circuit based on their own individual treatment technique. Specifically, as presently understood, the prior heretofore probeholder terminated the coaxial cable center conductor into a large brass tip which accepted the probe. The shield terminated where the center conductor connected to the end of the probeholder allowing RF energy to be coupled to the operator, as well as the patient.